The laws of physics underlying everyday life are, at one level of description, completely known, and can be summarized in a single elegant—if quite complex—equation. That's the claim physicist Sean Carroll, an SFI Fractal Faculty member, and External Professor, makes in a recent paper.
Objects in
our everyday world—people, planets, puppies—are made up of atoms and molecules.
Atoms and molecules, in turn, are made of elementary particles,
interacting via a set of fundamental forces. And these particles and forces are
accurately—and completely, Carroll argues—described by the principles of
quantum field theory, in a model known as the "Core Theory." All the
things we humans experience in our day-to-day lives—the warmth of sunlight, the
gravitational pull of the Earth, the kinetic energy required
to move our bodies through space—are beholden to and can be explained by Core
Theory.
Don't worry
that physicists will soon be out of their jobs, though. The Theory of
Everything is not yet in our hands. We will undoubtedly discover new particles
and new forces, and perhaps even phenomena that are completely outside the
domain in which our current understanding of physics operates. If we push
beyond our ordinary world into black
holes and other aspects of quantum gravity, there are indications that
quantum field theory might not be the right framework to describe them.
Similarly, it may not suffice to explain conditions in the early universe, or near
neutron stars or black holes, or phenomena such as dark matter and dark energy
that don't interact noticeably with human beings under ordinary circumstances.
Core Theory,
Equation 7 from the paper "The Quantum Field Theory on Which the Everyday World Supervenes."
Credit: Santa Fe Institute
But Carroll
argues that none of the discoveries needed to explain such phenomena will alter
our understanding of the physics that affects our everyday lives. Assuming
Carroll's claim is correct, it has a number of immediate implications. It means
there is no life after death, as the information in a person's mind is encoded
in the physical configuration of atoms in their body, and there is no physical
mechanism for that information to be carried away after death.
The problems
of consciousness must ultimately be answered in terms of processes that are
compatible with this underlying theory. And while historically, discoveries
of new particles and
forces have spurred technological innovations, Core Theory means that won't
happen going forward, since those discoveries won't be at a level to impact our
everyday lives.
Carroll
admits that he can't give an airtight proof for this, which would be
essentially impossible. But his arguments, he says, highlight the challenge
faced by those who think something beyond the Core Theory is required. He notes
that the dynamics summarized by the equation of the Core Theory are
"well-defined, quantitative, and unyielding, not to mention experimentally
tested to exquisite precision in a wide variety of contexts… Skeptics of the
claim defended here have the burden of specifying precisely how that equation
is to be modified. This would necessarily raise a host of tricky issues."